{
  "bibcode": "2023GCN.33418....1D",
  "body": "M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner\n(Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak\n(Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, J.-P.\nBreuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U.\nof Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo,\nM. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U.\nof Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H.\nPoon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos\nU.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G.\nFriss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi\n(Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss\n(Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.),\nH. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima\nU.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U.\nTokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.\n\n\nThe extremely bright long-duration GRB 230307A (Fermi/GBM detection: GCN\n33405, 33407, 33411, 33414; GECAM-B detection: GCN 33406; Solar Orbiter\nSTIX detection: GCN 33410; AGILE/MCAL detection: GCN 33412; IPN\ntriangulation: GCN 33413; AstroSat detection: GCN 33415; BALROG\nlocalization: GCN 33416) was observed by the GRBAlpha 1U CubeSat (Pal et\nal. Proc. SPIE 2020).\n\n\nThe detection was confirmed at the peak time 2023-03-07 15:44:12 UTC. The\nT90 duration measured by GRBAlpha is 25 s and the overall significance\nduring T90 reaches 305 sigma. GRBAlpha entered the outer Van Allen\nradiation belt during the tail part of the burst.\n\nThe peak count rate detected by GRBAlpha reaches almost 10 000 counts/s,\nwhich is nearly half of the peak count rate of 22 000 counts/s measured for\nGRB221009A.\n\n\nThe light curve obtained by GRBAlpha is available here:\nhttps://grbalpha.konkoly.hu/static/share/GRB230307A_GCN.pdf\n\n\nAll GRBAlpha detections are listed at:\nhttps://monoceros.physics.muni.cz/hea/GRBAlpha/\n\nGRBAlpha, launched on 2021 March 22, is a demonstration mission for a\nfuture CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector\nof GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a\nSiPM array, covering the energy range from ~50 keV to ~1000 keV. To\nincrease the duty cycle and the downlink rate, the upgrade of the on-board\ndata acquisition software stack is in progress. The ground segment is also\nsupported by the radio amateur community and it takes advantage of the\nSatNOGS network for increased data downlink volume.",
  "circularId": 33418,
  "createdOn": 1678274581000,
  "email": "500025@mail.muni.cz",
  "subject": "GRB 230307A: Detection by GRBAlpha",
  "submitter": "Marianna Dafcikova at Masaryk University  <500025@mail.muni.cz>",
  "eventId": "GRB 230307A"
}